Hydraulic Clutch Actuator Bypass Flow Limiting for Torque Surge Damping

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Solution Overview

Problem

Existing clutch control systems fail to adequately protect the vehicle's kinematic chain from sudden torque surges during clutch re-engagement, especially when the clutch pedal is released rapidly, which can lead to excessive stress and potential damage.

Innovation Solution

A clutch control device with an actuator that incorporates a flow limiter in a bypass pipe, allowing fluid to pass through a main pipe for automatic clutch operation and through a bypass for driver-controlled operation, limiting torque peaks by restricting fluid flow back to the transmitter during sudden clutch closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a flow limiter is integrated into the actuator, then the clutch control system protects against torque surges during sudden pedal release, but the device complexity increases

Engineering Contradiction:
Improveprotection against torque surgesVSAvoidactuator structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flow limiter is integrated into the actuator body, merging two separate components (actuator and flow limiter) into a single unified structure. This reduces the number of separate parts while maintaining the torque surge protection function, thereby addressing the complexity issue.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuator is designed to perform multiple functions: it controls clutch engagement/disengagement and simultaneously limits torque surges through the integrated flow limiter. This multi-functionality eliminates the need for separate dedicated torque limitation devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If the actuator includes a bypass with flow restrictor, then the clutch engagement is controlled during sudden pedal release, but the overall size of the clutch control system increases

Engineering Contradiction:
Improveclutch engagement controlVSAvoidclutch control system size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The bypass channel with flow restrictor is nested within the actuator body, with the flow restrictor integrated into the bypass passage. This nested arrangement allows the torque control function to be embedded within the existing actuator volume rather than adding external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The bypass channel and flow restrictor are combined into the actuator structure, merging the torque control function with the existing hydraulic control pathway, thereby minimizing additional volume requirements.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If the flow limiter is integrated into the actuator, then the number of components is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvenumber of componentsVSAvoidintegration precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The flow restrictor is designed as a localized feature within the actuator body, with specific geometric characteristics (such as restricted passage dimensions) that can be precisely controlled during manufacturing. This localized approach allows for focused precision in critical areas while maintaining overall manufacturability.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces the overall size and cost of the clutch control system while enhancing performance by damping sudden clutch re-engagement, thereby protecting the kinematic chain from excessive torque peaks and improving fuel efficiency through controlled freewheel functions.

Implementation Method 1

limiting torque peaks by restricting fluid flow back to the transmitter during sudden clutch closure

Methodology Applied
Scientific EffectFluid flow restriction:

Implementation Method 2

a hydraulic pressure transmitter, a hydraulic clutch operation receiver, and a control actuator, located in the clutch control circuit between the transmitter and the receiver

Methodology Applied
Scientific EffectHydraulic pressure transmission: Hydraulic Press

Data Source

PatentEP3415779B1Clutch control actuator
Publication Date: 2022.04.06 RENAULT SA
  • EP3415779B1 patent drawingFigure 1
  • EP3415779B1 patent drawingFigure 2A~3

AI summary

Clutch control actuator (5) disposed in a vehicle hydraulic clutch control circuit (9), between a pressure transmitter (3) and a hydraulic clutch operation receiver (10), characterized in that it has a main line (12) for passing fluid at constant flow rate, and a bypass line (12a) from the main line, incorporating a flow limiter (11) partially blocking the return fluid passage from the receiver (10) to the transmitter (3), during a sudden closure of the clutch (9).